This invention relates to an optical reading apparatus for optically reading characters, symbols, marks, and legends and the like carried on a recording element, and is most suitable for use in a card reader having a reading image sensor for reading the cards, checks and the like which carry the characters and the like, the reading image sensor being arranged so that its height can be adjusted while the cards, checks and the like are being moved.
Heretofore, the characters in a line could be caught within a visual field of the image sensor by manually operating the so-called "height adjustment wheels" provided for changing the height of a card track which is at the base of a card insertion slot. Upon turning the height adjustment wheels, the track height would be changed in relation to the card insertion slot by means of a helical ramp or cam, so that the different lines of characters on the cards could be accommodated irrespective of the type of the card, and the characters and the like on the card could be optically read, as shown in FIGS. 5, 6 and 9 of U.S. Pat. No. 4,396,902.
According to the aforementioned prior art, height adjustment wheels 63 are manually turned so that a track 65 is moved over its entire height on helical ramps 64, thus aligning the characters to be read with the image detector or sensor. However, it is not in fact possible to see where the center line of the image sensor is located; therefore it is difficult to properly align the center line with the characters. Moreover, the height adjustment wheels 63 are turned to raise the track 65 along the helical ramps 64 so that the adjustment wheels 63 are positioned under the track 65, which provides no means for determining whether optical array 73 in the image sensor exactly captures the character image.